DE1419246B2 - METHOD OF REMOVING FINE PARTICLES FROM GASES OR VAPORS - Google Patents

Description

1 2

The main patent relates to a fiber filter, where the particles are present as individual, independent droplets,

Diameters of the fibers within the range of according to patent 1,207,344, the method being thereby

5 to 50 μ is to remove sulfuric acid is characterized in that the filter with a liquid

mist with a particle size of less than 5 μ, is sprayed.

with the indication that the one with a silicone is 5 in German patent specification 549 340. already coated fiber filter has a density of 0.16, the removal of sulfur trioxide mist with an and consists of such fibers on which the use of a mineral filter is described, whereby the captured mist particles as individual independent mineral filters during operation with water droplets are present. is sprayed to affect the sulfur trioxide mist

As indicated in this main patent, io shows moist and, in order to thereby cause a detailed microscopic examination, that mist adheres to the filter. According to German Patent Specification 854 497, if a fine mist contains gases, mist of gases or vapors are sent through a fiber filter, the vapors are removed using a ceramic filter from any of the previously used for this purpose, which is also sprayed with water , used materials is made, e.g. B. Slag- 15 Here, too, by spraying the filter with wool, cotton or glass wool, whereby the through-water increases the effectiveness of the filter,
knife of the fibers of the filter in relation to the size. The mist droplets verder in the method according to the invention are selected so that they have a high cleaning effect, according to the mist, the mist that can be collected so that a spraying with a liquid to droplets the Wetting the fibers and increasing the cleaning power is not necessary. Make the film on them. This film is not the same - spraying with a liquid according to the previously thick, and at first glance it even seems that the present invention is primarily used to keep individual droplets on the fibers - the fiber filter contains aggressive substances from the . However, a more in-depth fiber shows rinse off.

Investigation that the droplets are not separated from each other 25 According to the invention, such a liquid are separate and independent, but that used, which physically dissolve the particles, emulein practically uninterrupted liquid film that yaws, disperses or with them a fine suspension of fibers surrounds, from a droplet to the sion, z. B. is able to form a colloidal suspension next extends. or reacts chemically with the particles, whereby

In contrast, with another type of fiber, they are dissolved, emulsified or dispersed. the the liquid, which is expediently "non-wettable", can also be referred to as emulsifying or dispersing be an extraordinary and very medium or contain a medium that is a colloidal surprising increase in the filtering effect produced by suspension of the particles. Water is respected. These are fibers on which the mist prefers.

individual, independent droplets is deposited, 35 The sprayed filters of the invention are for

which are not suitable (as in the case of the previously used »removal of liquid particles

wettable «fibers) have fiber filters described by a main bridging patent, though

Liquid film are connected. Such a drip is extremely good at removing fine mist

wise deposition of the mist occurs when the above are suitable, the disadvantage that they are easily through strong

mentioned wettable fibers. 40 corrosive, mist-containing gases or vapors

It was further stated that the problem would be grasped. This is how a fiber filter made of glass der Manufacture of a suitable fiber filter does not consist of fibers with a silicone surface in the course as one might suppose, it was simply solved by attacking the time by a gas that had a great deal of time will that a hydrophobic or water repellent amount of particles of concentrated sulfuric acid Fiber is applied. For example, it was included. This makes the choice and uses that silicone-treated glass wool and the possibility of those in the patents mentioned Polyethylene terephthalate fibers exceptionally effective filters are limited. In contrast, will same fiber filter result, while other substances, as according to the invention by spraying the fiber filter their Untreated glass wool, nylon staple fiber, poly- application possibilities improved, since with continuous vinyl chloride fiber and slag wool, as a filter for 50 spraying the filters these less of the chemical fine mist are not effective. Although polyvinyl is subject to action because of the reactive particles chloride fiber of all the fibers mentioned that are diluted with water in the liquid in the filter body, most repulsive (like a measurement of the main contact- Furthermore, the present invention is special angle between the fibers and 10% sulfur - also for the removal of solid particles such. B. acid), it is nevertheless not very suitable as a filter medium. For example, if in effective. Cells for the electrolysis of molten mixtures

It has now been found that the use of sodium chloride and calcium chloride diaphragms

the fiber filter according to the main patent are improved, a smoke is released that is fine

if the filter is opened while the particles of sodium oxide and some calcium chloride,

Operation with a liquid, expediently with water, containing 60% sodium chloride and chlorine. Also will

sprayed. a smoke that is fine, made almost entirely of sodium oxide

Thus, the invention also relates to a method for containing existing particles, obtained when removing sodium can be destroyed by fine particles from gases or residues in the incinerator. Steaming using a fiber filter, Such smoke is very harmful and has been the diameter of the fibers within a range 65 made numerous attempts at this smoke from 5 to 50 μ and effectively removing those coated with silicone. So the smoke got through a Fibers as a filter have a density of 0.16 and a filter made of slag wool fibers is sent, have the property that the mist collected - however, it has been found that such a filter

3. 4th

quickly becomes clogged with accumulated solids. This filter was also attacked by the small amounts of its polysiloxane groups, 16 to 27% of silicon- chlorine contained in the smoke. Contains cium-bonded chlorine, ie that the end-If one, however, a "non-wettable" fiber filter, permanent groups of the polymer still not hydro-expedient contain a methylchlorosilane residue lysed from polyethylene terephthalate fibers. Such materials or one made of glass fibers with an adhering SiIi- materials are commercially available. To an adherent konoberfläche used, which on the glass fibers with this silicone is successively with water the surface to be sprayed, this filter is in all respects when achieve, the fibers in a 2% ^e solution of the removal of Natriumoxydrauch be ig satisfactory. Silicones immersed in trichlorethylene run off. Furthermore, when using such filters, the io can be left and then dried ^{at HO 0 C.}
A method for removing the particles using an An embodiment of a device for removing

relatively small pressure drop is carried out removal of fine particles according to the invention is carried out in the. Although the filter according to the invention is explained using the drawing.

Can be applied to very fine liquids. In the drawing, 1 is a vessel made of mild steel with and particulate matter of exceptionally small size 15 of a rubber liner 2 and an inlet pipe 3 Particle size, e.g. B. less than 5 μ to remove for the contaminated gases or vapors. 4 is a They can also be used to remove significantly annular piping. In the pipeline 4 and larger particles, e.g. B. 25 μ and above, four spray nozzles 5 facing symmetrically around these, fitted, of which only two are shown for the sake of simplicity

The filters according to the invention must be made of "not". 6 is the inlet end of the conduit 4, through wettable "fibers are made, and examples of which the spray liquid on its way to the four different types of sprayed filters that pass through nozzles. 7 is a resin ring that holds the can be used are fiber filters made of glass sieve plate 8 on which the preformed filter fibers with an adhering silicone surface is 9. 10 is a sealed drain for the stand, and filters made of polyethylene terephthalate liquid after it has passed the filter, fibers consist; another useful non- and 11 is a synthetic resin pipe through which the wettable fiber is polyacrylonitrile fiber. contaminating particles released gas escapes. In

Preferably, such filters are used, the contaminated gas flows into this device pressed during their manufacture and heated in the same direction as the spray from above be that the chip present in the fibers 30 below. However, other arrangements can also be used need to be lifted. to be hit; E.g. one can use a vertical

The fiber filters will normally use a filter system and flow through this density of about 80 to 160 kg / m ³ , preferably top to bottom, while packing about 96 kg / m ³ . When the method for simultaneously horizontal the upstream removal of fine particles from gases or vapors 35 side sprays.

is carried out using such filters. The following examples serve to further illustrate the pressure drop in the range of 7.5 to 62.5 cm.
Water column.

However, good results can be achieved with a print example 1

waste from 7.5 to 37.5 cm of water column or even 40 in a plant for the production of sulfuric acid including, z. B. from 7.5 to 25 cm water column, the gases leaving the contact chambers were achieved will. initially chilled, then in a concentrated

The sulfuric acid applied to the glass fiber surface is absorbed and then sent by alkali-containing silicones can generally be used as organic silicon absorption towers. The sulfuric acid compounds are referred to, the polysiloxane 45 of the smoke-containing exhaust gas contained between 0.05 groupings. These can be on the glass and 0.1 g H ₂ SO ₄ / m ³ gas, and the fog particles in the form of silicone oils or silicone resins were consistently less than 2 μ in size; be applied. The designation "silicone oil" is supposed to be 10 percent by weight less than 1 μ. Glass fibers comprise liquid products, which by hydrolysis and with diameters lying in the range of 5 to 40 μ condensation of a substantially of dialkyl 50 were packed and in a form to a density dichlorosilanes existing of 96 kg / m ³ to form an intermediate 5 cm thick layer. It is also possible to produce pressed silicone oils. Subsequently, the glass fibers were to be in the _T ge, where alkyl heated by aryl and pressed state for 1 hour at 500 ° C. Those in the alkenyl groups are replaced. Silicone resins are heat stabilized mat was then taken out normally by hydrolysis of mixtures of 55, washed in trichlorethylene and then dialkyl and / or diaryldichlorosilanes and trialkyl in a 2% solution of silicone oil in trichlorethylene chlorosilanes, silicone resins can also be immersed, drained and at 110 ⁰ C geaus Alkyldichlorsilanen be obtained. Although that dries. The surface of the filter, which was presented to the word "resin" as a solid or semi-solid, impure gas flow, suggests that the condition suggests that silicone resins can also be approximately 0.93 m ³ .

be liquid products that only solidify if the prerequisites explained in the drawing have been

they are applied by heating further condensation instruction. The exhaust gas containing the mist throws. was from top to bottom through the filter with a

A special silicone oil that is used to achieve a speed of 280 m ³ / hour. m ² filter surface adhesive surface on glass fibers is suitable, 65 sent, with the pressure drop 11 cm water column consists of a product which was partially through. The filter was sprayed continuously with water for hydrolysis and condensation of a methylchlorosilane, the spray rate being obtained approximately as a mixture, which was mainly di-5.41 / hour / m ² filter area. While the filter

Claims (1)

5 6 in operation continuously for more than 1000 hours. B e i s ρ i e 1 4 was held, no visible smoke could be seen in the exhaust gas. Glass fibers with a particle size of 5 to 40 μ to be established. The sulfuric acid content of the packaging was packed and placed in a shape to a density gases was between 0.0005 and 0.001 g H ₂ SO ₄ / m ³ . of 96 kg / m ³ pressed, with a 5 cm thick layer In the following examples a device 5 was obtained. The glass fibers were then ^{applied, heated to 55O 0} C for 1 hour in the compressed state to carry out the described. Experiments on a smaller scale was suitable. This then the glass fibers, as in Example 1, with The device consisted essentially of a glass surface with an adhesive silicone surface. The filter Vessel containing an insert on which one was in the form of a flat cylindrical mat shaped filter was placed, this filter of io by 37.5 cm in diameter. a liquid was sprayed through a with from a burn-off basin for the destruction of a pipe provided with a single nozzle was inserted. Sodium residues were, as in Example 2, air withdrawn containing sodium oxide particles, wherein B e i s ρ i e 1 2 the concentration of the particles between 0.25 and 15 1 g / m ³ air. This air got through the filter Glass fibers with diameters lying in the range of 5 to 10 μ, which were continuously sprayed with water, were packed and in a form, the spraying speed being approximately a density of 160 kg / m ³ forming a 5 cm 24.4 to 48, 8 l / h / m ² filter area. The thick layer is compacted. Then this glass set in air was about 237 m ³ / hour / ^{m 2} filter surface fibers were subjected to a heat treatment and, as in 20, with a pressure drop of 17.5 to 25 cm water column. Example 1 with an adherent silicone surface water containing dissolved sodium hydroxide was seen. The filter was in the form of a flat cylindrical mat with a diameter of 37.5 cm on a mat below the filter in the device. subtracted the lying point. From a burn tank to the destruction of Das Filter was in operation for 3 months. During this Sodium residues were vented to the air, which was no visible amount of time in the exhaust gases Sodium oxide particles with a largest solid particle size were found. The amount of of about 9 μ, with 50 weight percent solids held was less than 0.001 g / m ³ , were smaller than 5 μ. The concentration of the particles ... fluctuated between 0.25 and 0.8 g / m ³ air. This ß e 1 s ρ 1 e ι D Air was passed through the polyethylene terephthalate fibers continuously with water in the range of sprayed filter sent, whereby the spray speed - 10 to 40 μ lying diameters were pre- speed was about 5.4 l / h / m ² filter area. The shrunk by the fibers without pressure to 16O ⁰ C Flow rate of air heated by the sprayed filter. The pre-shrunk fibers were was sent, fluctuated between 280 m ³ / hour ^{/ m 2} packed and pressed to a density of 96 kg / m ^3, Filter surface with a pressure drop of 40 cm water, whereby a 5 cm thick layer was obtained. the column and 205 m ³ / hour / ^{m 2} filter surface b; i a fibers were then in the compressed state Pressure drop of 35 cm water column. Heated to 140 ° C in one hour. The filter owned the Device below the point of the filter in the form of a flat cylindrical mat of 37.5 cm water was drawn off, the dissolved sodium diameter, Hydroxyd contained. 40 As in cells for the electrolysis of molten At no time during an experiment of mixtures of sodium and calcium chloride di- For 700 hours visible smoke phrases in the exhaust gas could be replaced, smoke formed, to be observed. The amount of any in the exhaust of the fine particles of sodium oxide and something solids contained was less than 0.001 g / m ³ . Contained calcium chloride, sodium chloride and chlorine. 45 The upper particle size of the contaminating particles Example 3 was less than 4.5 µ. 90 percent by weight were smaller than 3.5 μ and 50 percent by weight Polyethylene terephthalate fibers with in the range of less than 2 μ. The concentration of the particles 10 to 40 μ in diameter were pre- fluctuated between 0.25 and 1 g / m ³ air,
shrunk by the fibers, without having to-50 The filter was 2 months this were sammengedrückt to remove, for 1 hour at 200 ⁰ C smoke heated under the conditions described in Example 4 Bewurden. The pre-shrunk fibers were applied conditions. During this time, the packing was closed and ^{no visible amount of solid was compacted to a density of 160 kg / m 3} in the exhaust gas, a 5 cm thick filter being obtained. The amount of solid contained in the exhaust gas became. Then the fibers in the compacted 55 fabrics was less than 0.001 g / m ³ .
Condition heated to 200 ^° C. for 1 hour. The filter had ",
the shape of a flat cylindrical mat by i-atentansprucn.
37.5 cm in diameter. Process for removing fine particles The procedure described in Example 2 was carried out from gases or vapors using a Using this fiber filter with water as a 60 fiber filter, the diameter of the fibers Spray liquid repeatedly. is within a range of 5 to 50 μ and With a throughput of 231 m ³ / hour / ^{m 2} filter, the silicone-coated fibers act as a filter surface was the pressure drop 37.5 cm water density of 0.16 and the property pillar. During a test of 900 hours, the captured mist particles were found to be at no point in time at which individual, independent droplets are present from the filter emerging exhaust gas any visible smoke solid- Patent 1 207 344, thereby marked- posed. The amount of solid η e t contained in the exhaust gas that the filter is sprayed with a liquid substances was less than 0.001 g / m ³ . will. 1 sheet of drawings